Transcatheter aortic valve replacement for bicuspid aortic valve stenosis with first- and new-generation bioprostheses: A systematic review and meta-analysis

Background: Subjects with bicuspid aortic valve (BAV) have been excluded from transcatheter aortic valve replacement (TAVR) randomized trials. Methods: With this meta-analysis of observational studies we first compared TAVR outcomes of BAV vs. tricuspid aortic valve (TAV) patients, stratifying the results by device generation. Then, we looked for differences between balloon-expandable (BE) and self-expandable (SE) bioprostheses in BAV patients. Primary outcome was 30-day mortality. Secondary outcomes were 30-day stroke, moderate-severe paravalvular leakage, new pacemaker implantation, vascular complications and 1-year mortality. Results: Thirteen studies (11,032 patients, 7291 TAV and 3741 BAV) and seven studies (706 patients, 367 treated with BE, 339 with SE valve) met inclusion criteria. Thirty-day (OR = 1.13; 95% CI 0.88–1.46, p = 0.33) and 1-year mortality (OR = 1.02; 95% CI 0.77–1.37, p = 0.87) were similar between patients receiving TAVR for BAV or TAV. Subjects treated for BAV were at higher risk of conversion to conventional surgery (OR = 2.35; 95% CI 1.30–4.23, p = 0.005), implantation of a second valve (OR = 2.06; 95% CI 1.31–3.25; p = 0.002), moderate/severe paravalvular leakage (PVL) (OR = 1.67; 95% CI 1.29–2.17; p = 0.0001) and device failure (OR = 1.26; 95% CI 1.02–1.56; p = 0.04). Rates of adverse events decreased significantly with the use of new-generation devices, but outcome differences remained consistent. BAV patients treated with BE vs. SE valves had similar 30-day and 1-year mortality, stroke and moderate-severe PVL. Balloon-expandable valves were associated with lower rates of a second valve and new pacemaker implantation but carried higher risk of annular rupture. Conclusions: BAV patients treated with TAVR had similar 30-day and 1-year mortality as well as stroke and new pacemaker implantation rates compared to TAV subjects, but carried higher risk of moderate/severe PVL, conversion to surgery and device failure. Event rates significantly decreased with the use of new-generation devices, but TAVR still showed better procedural results in TAV compared to BAV.